Therapeutic inhaler



y 4, 1954 e. w. NEWTON ET AL 2,677,370

THERAPEUTIC INHALER Filed May 11, 1953 2 Sheets-Sheet l INVENTOR5 [la71? it? Alia/fan By (liar e5 11. 5/6/4/tfit HTTOR VEY Patented May 4,1954 r-Eao STATE TEN T OFFICE THERAPEUTIC INER Application May 11, 1953,Serial No. 354,150

(Cl. 12,8 I95) 10 Claims.

This application is a continuation in part of application Serial No.295,764, now abandoned, for Inhaler, filed June 26, 1952, by George W.Newton and Charles R. Stephen.

This invention relates to an inhaler for administering volatileanalgesics and anesthetics and more particularly to an inhaler adapted.to selfadministration by a patient.

Our inhaler is especially useful in the administration oftrichlorethylene, one of the more versatile analgesics in thepharmacological armamentarium. However, .our inhaler may be used for theadministration of other therapeutic agents which vaporize in a mannersimilar to trichlor ethylene.

Trichlorethylene is used in controlled concentrations with air or withair and oxygen for alleviating pain of any type. It has been foundparticularly useful during obstetrical labor, for minor surgicalprocedures, for dental treatments, and for the intractable pain ofcarcinoma.

In many such cases it is an advantage to permit the patient toadminister the analgesic himself. The psychological advantages ofselfadministration of safe yet effective concentrations of an analgesicby means of a reliable apparatus are obvious. When the patient realizesthat he himself can take steps to relieve hispain when it occurs, thefear of pain itself is usually eliminated. Several inhalers for theself=administration of trichlorethylene and similar analgesics andanesthetics have been developed, but none of them is believed to beentirely satisfactory from the viewpoint of portability, ease ofadjustment, variation of concentration of the administered agent,facility in handling by the patient and complete safety in use.

Prior inhalers have had one or more desirable characteristics but noneto our knowledge com bines them all to the degree found in the inhalerof the present invention. Our inhaler possesses several advantages overthose now available in the market:

1. It is much lighter in weight and thus easier to transport and easierfor the patient to handle.

2. It is smaller in diameter and hence easier for the patient to grasp.

3. It offers less resistance to inspiration and expiration, andaccordingly does not tire out the patient so easily.

4. The filling device is simple and involves no extra parts or screwdevices.

5. Variation of concentrations inhaled can be readily and simplyaccomplished.

6. The mechanism is simple and yet protected in such a way that droppingthe inhaler is not likely to cause damage.

7. In one embodiment of our invention a special inlet is providedwhereby oxygen can be administered to the patient along with thetrichlorethylene-air vapor mixture. This oxygen is mixed With theanalgesic vapor just as it enters the mask which the patient holds onhis face,

Perhaps themost common use to which these inhalers are put today is forthe relief of pain during obstetrical labor. When labor pains arewell-established, the inhaler is given to the prospective mother withappropriate explanationsof its value. She is told that when-she feels apain coming on, several breaths through the inhaler will relieve thepain of contractions. As labor pains become more severe, the attendingdoctor or nurse may increase the concentration of trichlorethylene byadjusting the intake mechanism in such a way that more air perinhalation passes over the trichlorethylene surface. The patient holdsthe inhaler herself and places the mask over her face from time to timeas the need for pain relief occurs. Should the patient believe that manyinhalations at a time will be of more benefit than a few, she may inhalesufiicient-vapor to lapse into unconsciousness. When this occurs, hermuscles relax, her hand falls away from her face and the mask with it,and in a few seconds she is conscious again. In this feature lies thesafety of self-administration in such a manner.

Other .conditions in which our inhaler is especially useful are:

1. Changing of painful dressings, especially burn dressings.

2. Testicular biopsies.

3. Cystoscopies.

4. Incision and drainage of abscesses.

5. Dressing and suture .of minor lacerations.

.6. Manipulation and reduction of simple fractures.

7. Dental treatments and operations.

8. Relief of pain in industrial accidents prior to and during transportto hospital.

9. Relief of pain in Wounded personnelprior to definitive care. Such apossibility could arise in a national catastrophe where casualties weretoo numerous for all to receive immediate treatment.

Our inhaler consists essentially .of .a tubular body having a sideoutlet near the top for connection with a conventional face mask, asingle central tube provided with circular frusto-conical exteriorbaiilesand an air inlet and vapor outlet, a wick surrounding the centraltube and baflles, an air inlet near the .top of the casing communicatingwith the face mask or other inhaling device for supplying vapor-freeair, and a bottom closure of the casing containing an air inlet portwhich also serves as a fill-hole and supplies air to the wick chamber.The inhaler has no loose parts which can be readily lost, such as screwcaps, Allen wrenches and the like. While in one modification a key isprovided for regulating the air intake and proportioning valve, this isof a simple form and is provided merely as a matter of convenience sincethe inlet valve may be readily adjusted by a screwdriver, pen knifeblade, hemostatic forceps, scissors or other readily available tool ofthis type. In spite of this ease of adjustment, the inlet valve is notaccessible to the patient and accordingly when the proper ratio ofanalgesic to air or oxygen has been set by the attending physician ornurse, there is little risk of unauthorized change of the setting by thepatient.

Three embodiments of our invention are described below and illustratedin the drawings, but the description and drawings are intended to beillustrative only and not to limit our invention, the scope or" which isdefined in the appended claims.

In the drawings:

Fig. 1 is an exploded view showing the essential parts of one form ofour inhaler disassembled;

Fig. 2 is a vertical axial section on line 2-2 of Fig. 3 in which thecourse of air and vapor currents is indicated by arrows;

Fig. 3 is a top and Fig. 4 a bottom view of the device;

Fig. 5 is an enlarged sectional detail of the retaining ring grooves ofthe regulating valve;

Fig. 6 is a side view of a modified form of inhaler;

Figs. '7 and 8 are respectively top and bottom views of thismodification;

Fig. 9 is a vertical section on the line 9-9 of Fig. 6;

Fig. 10 is a horizontal section on an enlarged scale on the line III0 ofFig. 6; and

Fig. 11 is a vertical section of a further modification of our inhalers.

The body I is a light-gauge sheet-metal tube having an orifice 2 nearthe top. This orifice opens into a side arm 3, which is adapted to beconnected with a conventional rubber face mask. The side arm is brazedor soldered to the body I, and a small auxiliary tube 4, which may beused for the administration of oxygen passes through the bottom of andis soldered or brazed to side arm 3.

A perforated top 5, having respiration holes 6, is crimped to the top ofbody tube I.

A bottom piece I is provided, having a central orifice 8 and bearingindicia 9. This bottom piece is lightly soldered at IE] to body I topermit removal for servicing.

A central tube assembly II consists of a single light-gauge cylindricaltube I2, provided with fixed exterior frusto-conical bailies. This tubeis brazed or soldered at I3 to bottom piece I. A wick I4 surrounds thetube assembly II and lies close to the inner wall of body I. Tube i2 isprovided with two air and vapor parts It and I6 in the form oftransverse slots, and with two frusto-conical bafiles I? and I8 eachprovided with a ring of perforations I9 and 2B.

In the lower end of tube I2 a valve plug 2I is rotatably mounted,retained by spring 22 seated in grooves 23 in the valve and 24 in tubeI2.

The sloping lower face of groove 24 tends to urge the half-end 25 of thevalve against the half-partition 26 in tube I2 and also permits removalof valve H with retaining spring 22 by a strong outward pull on the rod21 seated in the sides of valve plug 2|. The half-partition 26 in tubeI2 and the half-end 25 of valve plug 2! are wide enough to overlapslightly in the position shown in Fig. 2. In this position, pas sagethrough the valve plug directly into the tube is shut ofi, but passageis provided from the valve through cut away portion 25 of the valve plugand port I5 into the wick chamber 28, the annular space between tube I2and body I. When valve plug 2I is rotated it will be seen that access toWick chamber 28 through port I5 is shut off, but access is provideddirectly from the valve plug to the interior of tube I2.

The two frusto-conical perforated bafiles II and I8 have diameterssufliciently great to hold wick it against the inside walls of body I.As viewed in Figs. 1 and 2, baflie II is mounted base upwards and battleI8 base downwards. Two smaller exterior frusto-conical baflies 29 and 3Bare mounted base upwards on tube I2 respectively below and above portI5. Two similar bafiies 3| and 32 are mounted on tube I2 respectivelybelow and above port I6.

A partition 33 is soldered or brazed to tube I2. This partition iscircular and is of a diameter to form a sliding fit in body I, and toretain wick I5 against endwise movement; the partition also forms an endclosure of the wick chamber.

Tube I2 projects a short distance above partition 33 to afford a seatfor valve disc 34, which is retained loosely in operative position bybentover tangs 35. The disc 34 is made of thin brass shim stock or sheetplastic, and cooperates with the end of tube I2 to form a one-way valveto permit withdrawal of air and vapor from tube I2 by the user duringinspiration, but to prevent return of expired air into the tube.

Above the orifice 2 is mounted a second partition 38 which is heldfriction-tight in body I by means of small circumferentially spaced lugssprung into internal annular groove 31 in body I. Integral withpartition 36 is a short nipple 38 surrounding central orifice 39. Avalve cage 46 and valve disc ll, similar to valve cage 35 and valve disc35 are mounted on nipple 38 and cooperate therewith to form a one-wayexpiration valve.

A light chain 25 suitable for attaching by means of a snap hook 46 to awrist strap may be fastened in any suitable way to the upper part of theinhaler.

In use, a conventional face mask is connected with side arm 3 and valveplug 2I is turned by means of key 42 or otherwise to make index mark 53on valve plug aline with calibration mark Fill on bottom I ofinstrument. In this position, half-end 25 of the plug cooperates withhalf-partition 28 to shut of direct communication between interior ofvalve plug 2I and tube I2. Key 42 is merely a flat metal stamping ofoutline shown in Fig. 1 which fits with some play in the interior ofvalve plug 2 I between rod 21 and the adjacent side walls. Since key 42works equally well on either side of rod 2'1, no great care is needed ininserting it. Furthermore, as indicated above, if the key is mislaid,the valve can be adjusted by inserting a screwdriver or knife blade, orscissors blades, or by gripping rod 27 by hemostatic forceps or similarinstrument.

With the valve adjusted to ill position, the

inhaler is inverted, and the desired charge of trichlorethylene or othervolatile liquid medica ment is poured in through valve plug 2 The liquidflows into wick chamber H through port i and is distributed on wick Hiby inclining and rotating the device back and forth. It will be seenthat at this point even if all the liquid has not been absorbed by thewick, it is practically impossible for any of it to spill out of theinhaler, regardless of its position, because bottom i and partition 33in cooperation with wick it effectively seal the ends of Wick chamber Hand the frusto-conical bafiles deflect or divert liquid from ports 55and [6, whether the device is up right or inverted.

The inhaler is now ready for use at maximum dosage. When the userinhales, the reduction in pressure in the upper part of the devicecauses air to be drawn into wick chamber 28 through valve plug 2| andport it; here it is mixed with the analgesic or other vapor and isfurther drawn into tube #2 through port l6, through the oneway valve atthe top of tube 62, raising disc 35, and so through side arm 2 into theusers respiratory system. Simultaneously the reduced pressure seatsvalve disc 6! on nipple 38, thus preventing entrance of air though thetop of the instrument. On exhalation valve disc 35 is seated on the topof tube [2, thus preventing reentrance of the breath into the wickchamber, and valve disc ti is raised, thus permitting the exhalation tobe exhausted through perforations 6.

If a more moderate dosage is desired, the valve plug 2! is turned sothat the index alines with another of the calibration marks on bottom i(see Fig. 4) thus exposing more or less of passage 23 to the interior ofvalve plug 2 i. In this position part of the inhaled air passes directlyto the patient through tube l2, by-passing wick cham- 23 and thuspicking up no analgesic vapors; the remainder of the inhaled air picksup its quota of vapors in the wick chamber. It will be seen that byadjusting the position of valve plug 2 i, the inhaled mixturemay be madevery lean or very rich or of any intermediate concentration inaccordance with the users needs.

A wrist strap attached to chain may be fastened around the patientswrist to prevent accidental dropping of the inhaler.

A modified form of inhaler is illustrated in Figs. 6l0. Its principle ofoperation is substantially the same as that of the inhaler illustratedin Figs. 1-5, but it is provided with a different type of proportioningvalve.

The body 5i is provided with a horizontally elongated orifice 52 nearthe top, opening into side arm 53, which is adapted to be connected witha conventional rubber face mask or other inhaling device. A small hole53 in side arm 53 be provided to receive a bead chain for attaching awrist strap.

A perforated top 55, having respiration holes 56 of large area is fixedto the top of body 5.

A bottom piece 5-! is provided, having a central orifice 5S, bearingindicia 59. This bottom piece is lightly soldered at to body '5! topermit removal for servicing as in the previously illustrated inhaler.

A. central tube assembly El consists of a single cylindrical tube 52,provided with fixed exterior irusto-conieal bafiles and brazed orsoldered at 63 to bottom piece 57. A wick '64 surrounds the tubeassembly and lies close to the inner wall of body 5| Tube 62 is providedwith an air inlet port 65 6 and an air-vapor port communicating with thewick chambenand WithifillStO- COIliCEl 'bafiles projecting into the wickchamber. Bailles 67 and 68 have diameters sufiicientlygreat to hold wick54 against the inside wall of body 5|, and baffles is, 83, 8| and 82 areof less diameter. A solid partition it, just above air'inlet port 65separates the lower from the upper portion of the tube.

A top partition 83, soldered or brazedto tube 62, forms an end closureof the wick chamber and retains Wick 84 against endwise movement. Tube52 projects a short distance through and above partition I83 to afford aseat for one-way inhalation valve 84.

So far the construction of this embodiment of our invention has ingeneral followed that shown in Fig. 2, with the exception that in thisembodiment no proportioning valve is provided at the bottom of tube 62analogous to valve 2! in Fig. 2. Unlike partition 25, partitionlScompletely separates the upper and lower portions of tube 62.

In the embodiment of Figs. 6-10, regulation of vapor dosage is providedby proportioning valve 9i; in the head of the inhaler. This valvecomprises a vertically adjustable disc 85 having a range of travelpermitting it to be positioned entirely above or entirely below orifice52 or in any intermediate position. This disc has an upstanding nipple88 surrounding orifice 89, on which is mounted a one-way exhalationvalve 9|, similar in construction to valve 84.

Disc 35 is movable by means of thumb piece 92 (which may be of moldedplastic), traveling in slot 533 in body 5!, against pressure of spring9% on guide rod 95 which is retained by top 55. Guide rod 95 passesthrough a hole in the inner portion of thumb piece 92. Valve is retainedin a desired position by means of latch 96 having a locking lug 9'.which engages notches 98 in the edge of slot 93. Latch 9B is forcedoutwards by compression latch spring 99, which tends to keep lug 9iengaged with one of notches 98. Since latch 35 is recessed below thesurface of thumb piece 92, a small instrument is needed to depress it topermit movement of the proportioning valve, so it is not readilyaccessible to tampering by a patient using the inhaler. When valve 96 isin its top position with disc 86 above orifice 52, orifice 52 receivesonly the rich air-vapor from the wick chamber. As valve 90 is moveddownward, disc 85 passes across orifice 52, permitting more and more airto be drawn in through holes 56 in top 55 and blended with the air-vapormixture from the wick chamber. Finally, when the valve is in its bottomposition with disc 36 entirely below orifice 52, the latter receivesonly fresh air drawn in directly through holes 56.

The method of use of this model of the inhaler will be evident from thisdescription and from the description of use of the inhaler of Figs. 1-5.

A still further modification of our invention is illustrated in Fig. 11.This is intended particularly for dental use, the requirements of whichare somewhat different from those of general medical and surgical use.The dentist prefers an inhaling device in the form of a nose piece whichis strapped in place during the treatment or operation; this may beconnected with our inhaler by tubes and suitable fittings. Since thepatient in this case cannot regulate the dosage he receives by applyingand removing a mask as required, another regulating means must beprovided. This is done by modifying the proportioning valve; the lockingdevice of Figs. 9 and 10 is omitted and the valve is readily adjusted bythe 7 patients thumb. Should the patient become unconscious and sorelax, the valve is spring-biased to return automatically to a positionadmitting only fresh air to the inhaling device.

The construction of the body of the inhaler illustrated in Fig. 11 isthe same as that shown in Figs. 6-10. The modified proportioning valveis shown at Hill. A solid disc I36 is moved across orifice 52 by meansof thumb piece [52, to which it is attached and which slides verticallyin slot I 43 in body The disc and thumb piece are normally biassed bycompression spring I44 to take a bottom position with disc I36 beloworifice 52, thus admitting only fresh air to the inhaling device. As thepatient raises the disc against spring I44 by means of the thumb piece,more and more vapor from the wick chamber is admitted to the inhalingdevice. If pressure on the thumb piece is relaxed, disc I36 returns tothe all-fresh-air position. Spring Md surrounds guide pin I45 retainedby top piece 55 and passing through a hole in the inner extension of thethumb piece.

It will be noted that the inhaler of Fig. 11 lacks one-way valves 84 andill of Fig. 9. It is intended that this inhaler be used with an inhalingdevice incorporating one-way inlet and outlet valves, the outlet valvebeing preferably in or close to the nose piece and the inlet valve closeto our inhaler. This arrangement has the advantage that, with thesomewhat long connecting tubes required, there is a minimum of ebb andflow of air and vapor in the tubes and a minimum of rebreathing.However, alternate arrangements are practicable in which either one orboth oneway valves are incorporated in the inhaler and one or nonerespectively in the inhaling device.

The particular form of inhaling device used, whether face mask, nosepiece or other device, forms no part of this invention.

We claim:

1. An inhaler adapted to self-administration by the user of a mixture ofair with the vapor of an easily volatile liquid medicament, the inhalercomprising: a tubular body closed at both ends and having near the top aside arm communieating through an orific with the interior of theinhaler and adapted to fit an inhaling device; an air port at the top ofthe body; a combined intake air port and fill-hole at the bottom of thebody; a single longitudinal tube within the body of the inhaler, thelower end of the tube being connected with the inlet port at the bottomof the inhaler and the upper end of the tube terminating below the topof the inhaler; a first partition near the top of and surrounding thelongitudinal tube and positioned below the side arm of the inhaler, saidpartition, the longitudinal tube, and the bottom closure cooperatingwith the interior walls of the inhaler body to form a wick chamber; awick in the Wick chamber; a first port in the lower portion of thelongitudinal tube providing access from the outside air to the Wickchamber; a second port in the upper portion of the longitudinal tubeproviding access from the wick chamber to the space above said firstpartition; a wall in the longitudinal tube between said ports; and asecond partition in the body of the inhaler between said first partitionand the air port at the top of the body; said inhaler containing withinits body a proportioning valve adapted to regulate the ratio of vapor toair in the mixture inhaled by the user, said valve being accessible foradjustment 8 from the outside of the inhaler without disassembly of theinhaler.

2. An inhaler as defined in claim 1 in which the second partition in thetop of the inhaler is vertically movable across the side arm orifice, aslot in the side of the inhaler, a slideable thumb piec on the outsideof the inhaler having a portion projecting through the slot and attachedto the movable partition, said movable partition constituting aproportioning valve regulable by movement of the thumb piece.

3. An inhaler as defined in claim 2, having locking means for securingthe proportioning valve in a desired position.

4. Air inhaler as defined in claim 2 having a spring adapted to bias theproportioning valve to its lowest position.

5. An inhaler as defined in claim 1 in which the proportioning valve isconstituted of a rotatable valve plug in the bottom of the longitudinaltube, having a cut-away portion cooperating with the first port and witha cut-away portion of the Wall in the longitudinal tube to provideregulable access from the atmosphere through the valve plug to the wickchamber.

6. An inhaler as defined in claim 1 having a one-way inhalation valve atthe top of the longitudinal tube and a one-way exhalation valve in thesecond partition.

7. A11 inhaler adapted to self-administration by the user of a mixtureof air with the vapor of an easily volatile liquid medicament, theinhaler comprising: a cylindrical body closed at both ends and havingnear the top a side arm communicating through an orifice with theinterior of the inhaler and adapted to fit a face mask; an exhalationport at the top of the body; an inhalation port in the bottom closure ofthe body; a single longitudinal tube within the body of the inhaler, thelower end of the tube being fixedly connected with the inlet port in thebottom closure, the upper end of the longitudinal tube terminating belowthe top of the inhaler; a first partition near the topof and surroundingthe longitudinal tube and positioned below the side arm of the inhaler,said partition, the longitudi nal tube, and the bottom closurecooperating with the interior walls of the inhaler body to form anannular wick chamber; a wick in the Wick chamber; a second verticaladjustable partition in the body of the inhaler positioned between saidfirst partition and the top closure of the inhaler, said secondpartition being pierced by an exhalation passage and being adapted to bemoved vertically across the side arm orifice; a one-way inhalation valveat the top or" the longitudinal tube and a one-way exhalation valve inthe exhalation passage of said second adjustable partition; a first portin and near the bottom of the longitudinal tube providing access fromthe atmosphere to the wick chamber; a wall in the longitudinal tubeabove said first port; and a second port in the longitudinal tub abovesaid wall and providing access from the wick chamber through thelongitudinal tube to the space above said second partition.

8. An inhaler adapted to self-administration by the user of a mixture ofair with the vapor or" an easily volatile liquid medicament, the inhalercomprising: a cylindrical body closed at both ends and having near thetop a side arm adapted to fit a face mask; an exhalation port at the topof the body; an inhalation port in the bottom closure of the body; asingle longitudinal tube within the body of theinhaler, the lower end of9 the tube being fixedly connected with the inlet port in the bottomclosure and formin a housing for a rotatable proportioning and fillingvalve plug, the plug being positioned entirely within the body of theinhaler, the upper end ofthe longitudinal tube terminating below the topof th inhaler; a first partition near the top of and surrounding thelongitudinal tube and positioned below the side arm of the inhaler, saidpartition, the longitudinal tube, and the bottom closure cooperatingWith the interior walls of the inhaler body to form an annular wickchamber; a wick in the wick chamber; a second partition in the body ofthe inhaler positioned above said side arm and below said exhalationport, said second partition being pierced by an exhalation passage; aone-way inhalation valve at the top of the longitudinal tube and aone-way exhalation valve in the exhalation passage of said secondpartition; a first port in and near the bottom of the longitudinal tubecooperating with the valve plug to provide regulable access from theatmosphere through the valve plug to th wick chamber; a passage near thebottom of the longitudinal tube cooperating with the valve plug toprovide regulable access from the atmosphere through the valve plug tothe interior of the longitudinal tube; and a second port in thelongitudinal tube spaced above the first port and providin access fromthe wick chamber to the interior of the 10ngitudinal tube.

9. An inhaler as defined in claim 8 having in the wick chamber two pairsof inverted frustoconical bafiles positioned on the longitudinal tube,the baflies having a diameter substantially less than the interiordiameter of the inhaler body, one pair of said baflies being positionedrespectively closely above and below said first port in the longitudinaltub and the other pair of said baflles being positioned respectivelyclosely above and below said second port in said longitudinal tube.

10. An inhaler as defined in claim 8 in which the wick is a webpositioned against the interior walls of the body of the inhaler and inwhich two perforated circular baffles are positioned on the longitudinaltube, one near the bottom and one near the top, the baffles having adiameter such as to retain the wick against th inner walls of theinhaler.

No references cited.

